SENSITIVITY OF FORSYTHIA POLLEN TO THE FACTORS OF THE ENVIRONMENT OF THE MEGAPOLIS

Abstract

The sensitivity of the reproductive structures of Forsythia suspensa to the complex influence of undifferentiated environmental factors has been studied. The monitoring sites are located in 15 different park ecosystems in 6 administrative districts of Kyiv. Data from the Borys Sreznevsky Central Geophysical Observatory (air pollution index (API) and meteorological conditions for 2018-2020) were used to assess the conditions of the growth environment. The influence of a complex of ecologically important factors during the flowering of forsythia on the quality of the formed pollen is noted. Thus, growing plants for a long time in conditions with a low level of air pollution (API up to 5.0) in abnormal weather conditions in 2020, 40-50% less fertile grains were formed. And for plants, which grow in areas with increased level (API 5.0-7.0) and high level (API 7.0-14.0) of air pollution, the share of fertile grains in the pollen population decreased by 60-80%. In the closed bud, the pollen has higher resistance to a complex of exogenous growth factors. Forsythia plants, which are located in large parklands, lose less pollen quality in adverse weather conditions and affected by urbotechnogenic factors. F. suspensa is an acceptable indicator of the level of environmental pollution by the deviation of pollen fertility from the control value. In areas with high aerogenic load, for example, areas with large highways (Bus Station «Darnytsia»), as well as with a significant recreational load (Holosiivskyi Park, Recreation Park on the Olena Teliha Street) much smaller pollen is formed. It is noted that the conditions of forsythia growth affect the quantitative indicators of the formed pollen not only in the flower but also in the closed bud, which confirms the chronic effect of the complex of ingredients of aerotechnogenic emissions on plants of this species. The coefficient of sterility of pollen (CS) was used to objectively compare the data of 2019 and 2020 on the condition of the generative organs of F. suspensa in the studied areas. The calculation of the CS confirmed that in the closed bud pollen has a higher resistance to exogenous factors. In areas with high and increased levels of air pollution, during budding and flowering of plants (March-May,) there is a much higher CS of pollen of F. suspensа. Significant parkland territories of the city (for example, Holosiivskyi Park, Botanical Garden named after O. V. Fomin) provide less stressful conditions for growth and development of plants, even with the "very high" level of air pollution (ISA above 14.0) observed in April 2020 on this territory. The study of the susceptibility of F. suspensа pollen to growing conditions will be continued, as the prospects of using this species for bioindication of ecological status and zoning of park ecosystems of Kyiv according to the gradient of anthropogenic impact have been revealed.